Plasma-enhanced cyclic layer deposition process for barrier layers

ABSTRACT

In one embodiment, a method for forming a metal-containing material on a substrate is provided which includes forming a metal containing barrier layer on a substrate by a plasma-enhanced cyclical vapor deposition process, exposing the substrate to a soak process, and depositing a conductive material on the substrate by a second vapor deposition process. The substrate may be exposed to a silicon-containing compound (e.g., silane) during the soak process. In some examples, a metallic nitride layer may be deposited subsequent to the soak process and prior to the second vapor deposition process. In other examples, the metal containing barrier layer contains metallic titanium, the metallic nitride layer contains titanium nitride, and the conductive material contains tungsten or copper. The plasma-enhanced cyclical vapor deposition process may further include exposing the substrate to a nitrogen precursor, such as nitrogen, hydrogen, a nitrogen/hydrogen mixture, ammonia, hydrazine, or derivatives thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 11/151,699, filedJun. 13, 2005, and issued as U.S. Pat. No. 7,094,685, which is acontinuation of U.S. Ser. No. 10/118,664, filed Apr. 8, 2002, and issuedas U.S. Pat. No. 6,911,391, which claims benefit of U.S. Ser. No.60/352,191, filed Jan. 26, 2002, which are all herein incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to an apparatusand method of integration of titanium and titanium nitride layers.

2. Description of the Related Art

Reliably producing sub-micron and smaller features is one of the keytechnologies for the next generation of very large scale integration(VLSI) and ultra large scale integration (ULSI) of semiconductordevices. However, as the fringes of circuit technology are pressed, theshrinking dimensions of interconnects in VLSI and ULSI technology haveplaced additional demands on the processing capabilities. The multilevelinterconnects that lie at the heart of this technology require preciseprocessing of high aspect ratio features, such as vias and otherinterconnects. Reliable formation of these interconnects is veryimportant to VLSI and ULSI success and to the continued effort toincrease circuit density and quality of individual substrates.

As circuit densities increase, the widths of interconnects, such asvias, trenches, contacts, and other features, as well as the dielectricmaterials between, decrease to sub-micron dimensions (e.g., 0.20micrometers or less), whereas the thickness of the dielectric layersremain substantially constant, with the result of increasing the aspectratios (i.e., height divided by width) of the features. Many traditionaldeposition processes have difficulty filling sub-micron structures wherethe aspect ratio exceeds 4:1. Therefore, there is a great amount ofongoing effort being directed at the formation of substantiallyvoid-free and seam-free sub-micron features having high aspect ratios.

In the manufacture of integrated circuits, a titanium/titanium (Ti/TiN)film stack, a titanium nitride layer over a titanium layer, is oftenused as a liner barrier. For example, Ti/TiN film stack may be used toprovide contacts to the source and drain of a transistor. For example, aTi layer is deposited over a silicon substrate. A portion of the Tilayer, which is in contact with the silicon substrate, is converted totitanium silicide (TiSi_(x)) in situ or in an annealing step. A TiNlayer is deposited over the Ti layer. The titanium nitride layer is usedas a barrier layer to inhibit the diffusion of metals into regionsunderlying the barrier layer. A metal layer, such as a tungsten (W)layer, is deposited over the TiN layer.

A Ti layer and a TiN layer may be formed by chemical vapor depositionand/or physical vapor deposition techniques. One example of forming a TiLayer by chemical vapor deposition includes reacting titaniumtetrachloride (TiCl₄) with a hydrogen plasma. One example of forming aTiN layer by chemical vapor deposition includes reacting TiCl₄ with anitrogen reactant, such as a nitrogen plasma or ammonia (NH₃). Oneproblem with the use of TiCl₄-based chemistry used to form a TiN layerover a Ti layer is that reliability problems can occur. In particular,the TiN layer may have poor adhesion over the Ti layer, resulting inpeeling of the TiN layer off the Ti layer.

Therefore, there is a need for an improved apparatus and method ofintegration of titanium and titanium nitride layers.

SUMMARY OF THE INVENTION

Embodiments of the present invention generally relate to an apparatusand method of integration of titanium and titanium nitride layers. Oneembodiment includes providing one or more cycles of a first set ofcompounds, providing one or more cycles of a second set of compounds,and providing one or more cycles of a third set of compounds. One cycleof the first set of compounds includes introducing a titanium precursorand a reductant. One cycle of the second set of compounds includesintroducing the titanium precursor and a silicon precursor. One cycle ofthe third set of compounds includes introducing the titanium precursorand a nitrogen precursor. Another embodiment includes depositing atitanium layer utilizing titanium halide. Then, a passivation layer isdeposited over the titanium layer utilizing titanium halide. Thepassivation layer may comprise titanium silicide, titanium siliconnitride, and combinations thereof. Then, a titanium nitride layer isdeposited over the passivation layer utilizing titanium halide. Stillanother embodiment comprises depositing a titanium layer over a surfaceof a substrate. Then, the titanium layer is treated with a soak with asilicon precursor at a substrate temperature of about 550° C. or less toform a treated titanium layer. Then, a titanium nitride layer isdeposited over the treated titanium layer.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention are attained and can be understood in detail, a moreparticular description of the invention, briefly summarized above, maybe had by reference to the embodiments thereof which are illustrated inthe appended drawings. It is to be noted, however, that the appendeddrawings illustrate only typical embodiments of this invention and aretherefore not to be considered limiting of its scope, for the inventionmay admit to other equally effective embodiments.

FIG. 1 is a flow chart illustrating one embodiment of a process ofintegrating a titanium layer and a titanium nitride layer by forming atitanium silicide layer and/or a titanium silicon nitride layer betweenthe titanium layer and the titanium nitride layer.

FIG. 2A is a graph of the control signals of an exemplary process forcyclical deposition of a material.

FIG. 2B is a graph of the control signals of one exemplary process forchemical vapor deposition of a material.

FIG. 2C is a graph of one exemplary process of the control signals for acombined mode of cyclical deposition and chemical vapor deposition.

FIG. 3A is a flow chart illustrating one embodiment of a processutilizing a continuous flow of a purge gas to deposit a Ti layer, aTiSi_(x) layer, and a TiN layer by cyclical deposition in the samechamber.

FIG. 3B is a flow chart illustrating one embodiment of a processutilizing pulses of a purge gas to deposit a Ti layer, a TiSi_(x) layer,and a TiN layer by cyclical deposition in the same chamber.

FIG. 3C is a flow chart illustrating one embodiment of a processutilizing a continuous flow of a purge gas to deposit a Ti layer, aTiSi_(x)N_(y) layer, and a TiN layer by cyclical deposition in the samechamber.

FIG. 3D is a flow chart illustrating one embodiment of a processutilizing pulses of a purge gas to deposit a Ti layer, a TiSi_(x)N_(y)layer, and a TiN layer by cyclical deposition in the same chamber.

FIGS. 4 and 4A are drawings of an exemplary processing chamber that maybe used to perform cyclical deposition, chemical vapor deposition, or acombined mode of cyclical deposition and chemical vapor deposition.

FIG. 5 is a flow chart illustrating another embodiment of a process ofintegrating a Ti layer and a TiN layer by soaking a Ti layer with a flowof a silicon precursor prior to deposition of a TiN layer thereover.

FIG. 6 is a schematic cross-sectional view of one embodiment of anexemplary application of an integrated Ti/TiN film stack.

FIG. 7 is a schematic cross-sectional view of another embodiment of anexemplary application of an integrated Ti/TiN film stack.

DETAILED DESCRIPTION

Formation of a TiSi_(x) and/or a TiSi_(x)N_(y) film

FIG. 1 is a flow chart illustrating one embodiment of a process ofintegrating a titanium (Ti) layer and a titanium nitride (TiN) layer byforming a titanium silicide (TiSi_(x)) layer and/or a titanium siliconnitride (TiSi_(x)N_(y)) layer between the Ti layer and the TiN layer. Instep 10, a Ti layer may be formed over a substrate structure by cyclicaldeposition, chemical vapor deposition, or a combined mode of cyclicaldeposition and chemical vapor deposition. In step 20, a passivationlayer comprising titanium silicide and/or titanium silicon nitride maybe formed over the Ti layer by cyclical deposition, chemical vapordeposition, or a combined mode of cyclical deposition and chemical vapordeposition. In step 30, a TiN layer may be formed over the passivationlayer by cyclical deposition, chemical vapor deposition, or a combinedmode of cyclical deposition and chemical vapor deposition.

Not wishing to be bound by theory, it is believed that the TiSi_(x)layer or TiSi_(x)N_(y) helps protect the interface between the Ti layerand a subsequently deposited TiN layer resulting in improved adhesion ofthe TiN layer thereover. In the embodiment in which TiN is depositedutilizing a titanium halide, it is believed that the TiSi_(x) layer orTiSi_(x)N_(y) reduces the attack of the halide from the titanium halideused during deposition of TiN and thus provides a Ti/TiN film stack withimproved adhesion.

The term “substrate structure” as used herein is intended to include anyworkpiece upon which film processing is performed and may be used todenote a substrate, such as a semiconductor substrate or a glasssubstrate, as well as other material layers formed on the substrate,such as a dielectric layer. The term “cyclical deposition” as usedherein refers to the sequential introduction of one or more compounds todeposit a thin layer over a structure and includes processing techniquessuch as atomic layer deposition. Compounds can be reactants, reductants,precursors, catalysts, and mixtures thereof. Sequentially providingcompounds may result in the adsorption of thin layers of the compoundsover a substrate structure. The sequential introduction of compounds maybe repeated to deposit a plurality of thin layers forming a conformallayer to a desired thickness. The terms “adsorption” and “adsorb” asused herein are defined to include chemisorption, physisorption, or anyattractive and/or bonding forces which may be at work and/or which maycontribute to the bonding, reaction, adherence, or occupation of aportion of a surface of a substrate structure. The term “chemical vapordeposition” as used herein refers to deposition of materials in aprimarily gas-phase and/or thermal co-reaction of compounds to form alayer and includes plasma enhanced and non-enhanced processes. A mode ofdeposition combining cyclical deposition and chemical vapor depositionmay also be performed.

FIG. 2A is a graph of the control signals of an exemplary process forcyclical deposition of a material. One cycle 310 comprises introducing apulse 312 of a first compound 313 into a chamber by opening and closinga valve providing the first compound. After the pulse of the firstcompound, a pulse 314 of a second compound 315 is introduced into thechamber by opening and closing a valve providing the second compound.The cycle 310 may be repeated to deposit a desired thickness of thematerial. The pulses 312 of the first compound 313 and the pulses 314 ofthe second compound 315 may be delivered with or without a carrier gas.Examples of carrier gases which may be used include, but are not limitedto, helium (He), argon (Ar), nitrogen (N₂), hydrogen (H₂), and mixturesthereof. In one embodiment, the pulses 312 of the first compound 313 andthe pulses 314 of the second compound 315 may be dosed into a continuousflow of a purge gas. Examples of purge gases which may be used include,but are not limited to, helium (He), argon (Ar), nitrogen (N₂), hydrogen(H₂), and mixtures thereof. In other embodiments, pulses 312 of thefirst compound 313 and pulses 314 of the second compound 315 may beseparated by pulses of a purge gas. In still other embodiments, pulses312 of the first compound 313 and pulses 314 of a second compound 315may be separated by pump evacuation alone. In other embodiments,cyclical deposition comprises providing pulses of more than twocompounds.

FIG. 2B is a graph of the control signals of one exemplary process forchemical vapor deposition of a material. Chemical vapor deposition of amaterial may comprise introducing a first compound 323 and a secondcompound 325 simultaneously to a chamber by opening a valve providingthe first compound and by opening a valve providing the second compound.The first compound and the second may be delivered with or without acarrier gas. Examples of carrier gases which may be used include, butare not limited to, helium (He), argon (Ar), nitrogen (N₂), hydrogen(H₂), and mixtures thereof. In other embodiments, chemical vapordeposition comprises providing more than two compounds.

FIG. 2C is a graph of one exemplary process of the control signals for acombined mode of cyclical deposition and chemical vapor deposition. Onecycle 330 comprises introducing at least one pulse 332 of a firstcompound 333 by opening and closing a valve providing the first compoundand introducing pulses 334 of a second compound 335 by opening andclosing a valve providing the second compound. One or more pulses 334 aof the second compound 335 at least partially overlap with one or morepulses 332 of the first compound 333 in which the valve providing thefirst compound and the valve providing the second compound are both openat the same time for a period of time. One or more pulses 334 b , 334 cof the second compound 335 do not overlap with one or more pulses 332 ofthe first compound 333 in which the valve providing the first compoundis closed for a period of time while the valve providing the secondcompound is open. The cycle 330 may be repeated to deposit a desiredthickness of the material. The pulses 332 of the first compound 333 andthe pulses 334 of the second compound 335 may be delivered with orwithout a carrier gas. Examples of carrier gases which may be usedinclude, but are not limited to, helium (He), argon (Ar), nitrogen (N₂),hydrogen (H₂), and mixtures thereof. In one embodiment, the pulses 332of the first compound 333 and the pulses 334 of the second compound 335may be dosed into a continuous flow of a purge gas. Examples of purgegases which may be used include, but are not limited to, helium (He),argon (Ar), nitrogen (N₂), hydrogen (H₂), and mixtures thereof. In otherembodiments, pulses 332 of the first compound 333 and pulses 334 of thesecond compound 335 may be separated by pulses of a purge gas. In stillother embodiments, pulses 332 of the first compound 333 and pulses 334of a second compound 335 may be separated by pump evacuation alone. Inone aspect, a first compound and a second compound are delivered atseparate times to the substrate to provide a deposition process similarto cyclical deposition. In another aspect, a first compound and a secondcompound are delivered at the same time to the substrate to provide adeposition process similar to chemical vapor deposition. In otherembodiments, a combined mode of cyclical deposition comprises providingpulses of more than two compounds.

Other embodiments of a combined mode of cyclical deposition and chemicalvapor deposition are possible. For example, one cycle may compriseproviding one pulse of a first compound and one pulse of a secondcompound in which the pulse of the first compound and the pulse of thesecond compound only partially overlap in time by opening a valveproviding the first compound, then opening a valve providing the secondcompound, then closing the valve providing the first compound, and thenclosing the valve providing the second compound.

FIGS. 2A and 2C show the duration of pulses of compounds provided over arelative length of time, show a specific order of pulses, and show aspecific number of pulses per cycle. In other embodiments, otherrelative lengths of time, other order of the pulses, and other number ofpulses are possible.

In certain embodiments, deposition of Ti, whether by cyclicaldeposition, by chemical vapor deposition, or by a combined mode ofdeposition, comprises utilizing a titanium precursor and a reductant.The titanium precursor preferably comprises titanium tetrachloride(TiCl₄). Examples of other titanium containing compounds include, butare not limited to, titanium iodide (Til₄), titanium bromide (TiBr₄),other titanium halides, tetrakis(dimethylamido) titanium (TDMAT),tetrakis(diethylamido) titanium (TDEAT), other titanium organiccompounds, and derivatives thereof. The reductant comprises a hydrogenplasma. The hydrogen plasma is preferably provided by utilizing ahydrogen gas (H₂). Other hydrogen containing gases which may also beused include silane (SiH₄), borane (BH₃), diborane (B₂H₆), andtriborane, among others.

In certain embodiments, deposition of TiSi_(x), whether by cyclicaldeposition, by chemical vapor deposition, or by a combined mode ofdeposition, comprises utilizing a titanium precursor and a siliconprecursor. The titanium precursor preferably comprises TiCl₄. Othertitanium precursors may be used, such as the titanium precursorsdescribed above in regards to the deposition of Ti. The siliconprecursor preferably comprises silane (SiH₄). Other silicon containingcompounds include, but are not limited to disilane (Si₂H₆), chlorosilane(SiH₃Cl), dichlorosilane (SiH₂Cl₂), trichlorosilane (SiHCl₃), silicontetrachloride (SiCl₄), hexachlorodisilane (Si₂Cl₆), and derivativesthereof.

In certain embodiments, deposition of TiSi_(x)N_(y), whether by cyclicaldeposition, by chemical vapor deposition, or by a combined mode ofdeposition, comprises utilizing a titanium precursor, a siliconprecursor, and a nitrogen precursor. The titanium precursor preferablycomprises titanium tetrachloride (TiCl₄) and the silicon precursorpreferably comprises silane (SiH₄). Other titanium precursors andsilicon precursors may be used, such as the titanium precursors andsilicon precursors described above in regards to the deposition of Tiand TiSi_(x). The nitrogen precursor preferably comprises ammonia (NH₃).Examples of other nitrogen precursors include, but are not limited tohydrazine (N₂H₄), other N_(x)H_(y) compounds with x and y beingintegers, dimethyl hydrazine ((CH₃)₂N₂H₂), t-butylhydrazine (C₄H₉N₂H₃),phenylhydrazine (C₆H₅N₂H₃), 2,2′-azotertbutane ((CH₃)₆C₂N₂), ethylazide(C₂H₅N₃), and derivatives thereof.

In certain embodiments, deposition of TiN, whether by cyclicaldeposition, by chemical vapor deposition, or by a combined mode ofdeposition, comprises utilizing a titanium precursor and a nitrogenprecursor. The titanium precursor preferably comprises titaniumtetrachloride (TiCI₄). Other titanium precursors may be used, such asthe titanium precursors described above in regards to the deposition ofTi. The nitrogen precursor preferably comprises a nitrogen plasma, NH₃,or combinations thereof. Examples of other nitrogen precursors include,but are not limited to hydrazine (N₂H₄), other N_(x)H_(y) compounds withx and y being integers, dimethyl hydrazine ((CH₃)₂N₂H₂),t-butylhydrazine (C₄H₉N₂H₃), phenylhydrazine (C₆H₅N₂H₃),2,2′-azotertbutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃) and derivativesthereof. Examples of other nitrogen containing gases which may also beused to generate a nitrogen plasma include, but are not limited to, NH₃,N_(x)H_(y) with x and y being integers (e.g., hydrazine (N₂H₄)), amixture of hydrogen gas (H₂) and nitrogen gas (N₂), mixtures thereof,other gases or gas mixtures containing hydrogen and nitrogen.

Referring to FIG. 1, in one embodiment, step 10, step 20, and step 30are performed in separate chambers. In another embodiment, two or moreof the steps 10, 20, 30 are performed in the same chamber. In stillanother embodiment, all of the steps 10, 20, 30 are performed in thesame chamber.

FIG. 3A is a flow chart illustrating one embodiment of a processutilizing a continuous flow of a purge gas to deposit a Ti layer, aTiSi_(x) layer, and a TiN layer by cyclical deposition in the samechamber. As shown in step 602, a substrate is provided to the processchamber. The process chamber conditions, such as for example thesubstrate temperature and pressure, may be adjusted. In step 604, apurge gas stream is established within the process chamber. Referring tostep 606, after the purge gas stream is established within the processchamber, a pulse of a Ti precursor, such as TiCI₄, is added or dosedinto the purge gas stream. In step 608, after the pulse of the Tiprecursor a pulse of a reductant, such as a hydrogen plasma, is dosedinto the purge gas stream. Step 606 and step 608 are repeated until apredetermined number of cycles are performed to form a Ti layer.Referring to step 610, after a predetermined number of cycles of step606 and step 608 are performed, another pulse of the Ti precursor isdosed into the purge gas stream. In step 612, after the pulse of the Tiprecursor, a pulse of a Si precursor, such as a SiH₄, is dosed into thepurge gas stream. Step 610 and step 612 are repeated until apredetermined number of cycles are performed to form a TiSi_(x) layer.Referring to step 614, after a predetermined number of cycles of step610 and step 612 are performed, another pulse of the Ti precursor isdosed into the purge gas stream. In step 616, after the pulse of the Tiprecursor, a pulse of a nitrogen precursor, such as NH₃ or a nitrogenplasma, is dosed into the purge gas stream. Step 614 and step 616 arerepeated until a predetermined number of cycles are performed to form aTiN layer.

FIG. 3B is a flow chart illustrating one embodiment of a processutilizing pulses of a purge gas to deposit a Ti layer, a TiSi_(x) layer,and a TiN layer by cyclical deposition in the same chamber. As shown instep 622, a substrate is provided to a process chamber. The processchamber conditions, such as for example the substrate temperature andpressure, may be adjusted. In step 624, a pulse of a purge gas isprovided to the process chamber. Referring to step 626 after the pulseof the purge gas, a pulse of a Ti precursor, such as TiCI₄, is providedto the process chamber. In step 628, after the pulse of the Tiprecursor, another pulse of the purge gas is provided. In step 630,after the pulse of the purge gas, a pulse of a reductant, such as ahydrogen plasma, is provided. Steps 624, 626, 628, and 630 are repeateduntil a predetermined number of cycles are performed to form a Ti layer.Referring to step 632, after a predetermined number of cycles of steps624, 626, 628, and 630 are performed, another pulse of the purge gas isprovided to the process chamber. Referring to step 634, after the pulseof the purge gas, another pulse of the Ti precursor is provided to theprocess chamber. In step 636, after the pulse of the Ti precursor,another pulse of the purge gas is provided. In step 638, after the pulseof the purge gas, a pulse of a silicon precursor, such as silane (SiH₄),is provided. Steps 632, 634, 636, and 638 are repeated until apredetermined number of cycles are performed to form a TiSi_(x) layer.Referring to step 640, after a predetermined number of cycles of steps632, 634, 636, and 638 are performed, another pulse of the purge gas isprovided to the process chamber. Referring to step 642, after the pulseof the purge gas, another pulse of the Ti precursor is provided to theprocess chamber. In step 644, after the pulse of the Ti precursor,another pulse of the purge gas is provided. In step 646, after the pulseof the purge gas, a pulse of a pulse of a nitrogen precursor, such asNH₃ or a nitrogen plasma, is provided. Steps 640, 642, 644, and 646 arerepeated until a predetermined number of cycles are performed to form aTiN layer.

FIG. 3C is a flow chart illustrating one embodiment of a processutilizing a continuous flow of a purge gas to deposit a Ti layer, aTiSi_(x)N_(y) layer, and a TiN layer by cyclical deposition in the samechamber. As shown in step 652, a substrate is provided to the processchamber. The process chamber conditions, such as for example thesubstrate temperature and pressure, may be adjusted. In step 654, apurge gas stream is established within the process chamber. Referring tostep 656, after the purge gas stream is established within the processchamber, a pulse of a Ti precursor, such as TiCl₄, is added or dosedinto the purge gas stream. In step 658, after the pulse of the Tiprecursor a pulse of a reductant, such as a hydrogen plasma, is dosedinto the purge gas stream. Step 656 and step 658 are repeated until apredetermined number of cycles are performed to form a Ti layer.Referring to step 660, after a predetermined number of cycles of step656 and step 658 are performed, another pulse of the Ti precursor isdosed into the purge gas stream. In step 662, after the pulse of the Tiprecursor, a pulse of a Si precursor, such as SiH₄, and a pulse of anitrogen precursor, such as NH₃, is dosed into the purge gas stream. Thepulses of the Si precursor and the nitrogen precursor may be introducedseparately or may be introduced in which the pulses at least partiallyoverlap in time. Step 660 and step 662 are repeated until apredetermined number of cycles are performed to form a TiSi_(x)N_(y)layer. Referring to step 664, after a predetermined number of cycles ofstep 660 and step 662 are performed, another pulse of the Ti precursoris dosed into the purge gas stream. In step 666, after the pulse of theTi precursor, another pulse of the nitrogen precursor is dosed into thepurge gas stream. Step 664 and step 666 are repeated until apredetermined number of cycles are performed to form a TiN layer.

FIG. 3D is a flow chart illustrating one embodiment of a processutilizing pulses of a purge gas to deposit a Ti layer, a TiSi_(x)N_(y)layer, and a TiN layer by cyclical deposition in the same chamber. Asshown in step 672, a substrate is provided to a process chamber. Theprocess chamber conditions, such as for example the substratetemperature and pressure, may be adjusted. In step 674, a pulse of apurge gas is provided to the process chamber. Referring to step 676after the pulse of the purge gas, a pulse of a Ti precursor, such asTiCl₄, is provided to the process chamber. In step 678, after the pulseof the Ti precursor, another pulse of the purge gas is provided. In step680 after the pulse of the purge gas, a pulse of a reductant, such as ahydrogen plasma, is provided. Steps 674, 676, 678, and 680 are repeateduntil a predetermined number of cycles are performed to form a Ti layer.Referring to step 682, after a predetermined number of cycles of steps674, 676, 678, and 680 are performed, another pulse of the purge gas isprovided to the process chamber. Referring to step 684, after the pulseof the purge gas, another pulse of the Ti precursor is provided to theprocess chamber. In step 686, after the pulse of the Ti precursor,another pulse of the purge gas is provided. In step 688, after the pulseof the purge gas, a pulse of a silicon precursor, such as silane (SiH₄),and a pulse of a nitrogen precursor, such as ammonia (NH₃), is provided.The pulses of the Si precursor and the nitrogen precursor may beintroduced separately or may be introduced in which the pulses at leastpartially overlap in time. Steps 682, 684, 686, and 688 are repeateduntil a predetermined number of cycles are performed to form aTiSi_(x)N_(y) layer. Referring to step 690, after a predetermined numberof cycles of steps 682, 684, 686, and 688 are performed, another pulseof the purge gas is provided to the process chamber. Referring to step692, after the pulse of the purge gas, another pulse of the Ti precursoris provided to the process chamber. In step 694, after the pulse of theTi precursor, another pulse of the purge gas is provided. In step 696,after the pulse of the purge gas, another pulse of a pulse of a nitrogenprecursor is provided. Steps 690, 692, 694, and 696 are repeated until apredetermined number of cycles are performed to form a TiN layer.

In regards to FIGS. 3A-3D, the same Ti precursor is preferably used todeposit a Ti layer, a TiSi_(x)/TiSi_(x)N_(y) layer, and a TiN layer. Forexample, TiCl₄ may be used to deposit a Ti layer, aTiSi_(x)/TiSi_(x)N_(y) layer, and a TiN layer. FIGS. 3A-3D show thedeposition of a Ti layer, a TiSi_(x)/TiSi_(x)N_(y) layer, and a TiNlayer in a single chamber. In other embodiments, deposition of a Tilayer, a TiSi_(x)/TiSi_(x)N_(y) layer, and a TiN layer may be performedin more than one chamber. For example, two or more chambers may be usedto deposit a Ti layer, a TiSi_(x)/TiSi_(x)N_(y) layer, and a TiN layer.FIGS. 3A-3D show deposition of a Ti layer, a TiSi_(x)/TiSi_(x)N_(y)layer, and a TiN layer by cyclical deposition. In other embodiments,each layer may be deposited by the same or different depositiontechnique selected from the group including cyclical deposition,chemical vapor deposition, and a combined mode of cyclical depositionand chemical vapor deposition.

FIGS. 4 and 4A are drawings of an exemplary processing chamber 100 thatmay be used to perform cyclical deposition, chemical vapor deposition,or a combined mode of cyclical deposition and chemical vapor deposition.Other chambers may also be used. The chamber 100 comprises a chamberbody 102 including a substrate support 112 having a substrate receivingsurface 111 to support a substrate 110. The chamber may be adapted toheat the substrate 110, such as by a heated substrate support or byusing heat lamps. A gas distribution system 130 is disposed at an upperportion of the chamber body 102 to provide a gas to the chamber 100. Thegas distribution system 130 comprises a gas box 132, a top shower plate160 positioned below the gas box 132, and a bottom shower plate 170positioned below the top shower plate 160.

FIG. 4A is a schematic partial cross-sectional view of a portion of thegas box 132, a portion of the top shower plate 160, and a portion of thebottom shower plate 170 of FIG. 4. In reference to FIGS. 4 and 4A, thegas box 132 comprises a central gas channel 137 and a plurality of outergas channels 143. The central gas channel 137 provides one discrete pathfor the flow of one or more gases through the gas box 132 while theouter channels 143 provides another discrete path for the flow of one ormore gases through the gas box 132. The central gas channel 137 iscoupled to a first gas source 135 (FIG. 4) through valve 136 (FIG. 4).The central gas channel 137 has a first gas outlet 138 and is adapted todeliver a first gas from the first gas source 135 to a gas conduit 210.The term “gas” as used herein is intended to mean a single gas or a gasmixture. The outer gas channels 143 are coupled to a second gas source141 (FIG. 4) through valve 142 (FIG. 4). The outer gas channels 143 havesecond gas outlets 144 and are adapted to deliver a second gas from thesecond gas source 141 to the top shower plate 160. Preferably, thesecond gas outlets 144 of the outer gas channels 143 are adapted todeliver the second gas proximate a central portion of the top showerplate. Gas sources 135, 141 may be adapted to store a gas or liquidprecursor in a cooled, heated, or ambient environment. The valves 136,142 control delivery of the first gas and the second gas into thecentral gas channel 137 and the outer gas channels 143 respectively andmay be electrically controlled valves, pneumatically controlled valves,piezoelectric valves, or other suitable valves. In another embodiment, athird gas source may be coupled to the outer gas channels 143 toprovided a third gas to the top shower plate 160 or may be coupled tothe central gas channel 137 to provided a third gas to the gas conduit210.

Referring to FIG. 4A, the top shower plate 160 has a plurality of holes162 to accommodate a gas flow therethrough from the outer gas channels143 of the gas box 132 to the bottom shower plate 170. Referring to FIG.4, the top shower plate 160 is separated from the bottom shower plate170 by an insulator 164 to electrically insulate the top shower plate160 from the bottom shower plate 170. The bottom shower plate 170 may bedisposed on an upper portion of the chamber body 102, such as on a lidrim 166 disposed on the chamber body 102. The lid rim 166 comprises aninsulating material to electrically insulate the bottom shower plate 170from the chamber body 102. The gas conduit 210 is disposed through anaperture 163 in the top shower plate 160 and is disposed on the bottomshower plate 170. The gas conduit 210 is made of an insulating materialto prevent electrical coupling of the top shower plate 160 and thebottom shower plate 170.

As shown in FIG. 4A, the bottom shower plate 170 comprises a first piece172 connected to a second piece 180. The first piece 172 has a pluralityof holes 174 to provide a flow of a gas therethrough. The second piece180 comprises a plurality of columns 182 having column holes 183 formedtherethrough and a plurality of grooves 184 having groove holes 185formed therethrough. The top surface of the columns 182 are connected tothe bottom surface of the first piece 172 so that the column holes 183align with the holes 174 of the first piece 172. Therefore, one discretepassageway is provided through the holes of the first piece 172 andthrough the column holes 183 of the columns 182 to deliver a gas flowfrom the top shower plate 160 to the substrate receiving surface 111.The aperture 175 is formed through the first piece 172 and aligns withthe grooves on the second piece 180. Therefore, another discretepassageway is provided through the aperture 175 of the first piece 172and through the grooves 184 and groove holes 185 of the second piece 180to deliver a gas flow from the gas conduit 210 to the substratereceiving surface 111.

Referring to FIG. 4, a power source 190 may be coupled to the top showerplate 160 through the gas box 132 to provide a power electrode and thebottom shower plate 170 may be grounded to provide a ground electrode.The power source 190 may be an RF or DC power source. An electric fieldmay be established between the top shower plate 160 and the bottomshower plate 170 to generate a plasma from the gases introduced betweenthe top shower plate 160 and the bottom shower plate 170. The powersource 190 may be coupled to a matching network 194 to control deliveryof power to the power source 190. The power source 190 may selectivelyprovide power to selectively perform plasma and non-plasma processes.

In another embodiment, the bottom shower plate 170 may be optionallycoupled to a power source 192 in addition to the power source 190coupled to the top shower plate 160 and may be selectively powered orgrounded. The power sources 190 and 192 are coupled to the matchingnetwork 194 to control delivery of any amount of power to the powersource 190 and to control delivery of any amount of power to the powersource 192. In one aspect, the matching network 194 may control thedelivery of power to the power sources 190,192 so that the top showerplate 160 and the bottom shower plate 170 are at the same orsubstantially the same potential. With a grounded substrate support 112,the top shower plate 160 and the bottom shower plate 170 act as oneelectrode and the substrate support 112 acts as another electrode ofspaced apart electrodes in which an electric field is establishedbetween the bottom shower plate 170 and the substrate support 112 togenerate a plasma from the gases introduced between the bottom showerplate 170 and the substrate support 112. Therefore, power may beselectively provided to power sources 190, 192 to selectively generate aplasma between the top shower plate 160 and the bottom shower plate 170or between the bottom shower plate 170 and the substrate support 112.Thus, the power sources 190, 192 may selectively provide power toselectively perform plasma and non-plasma processes.

A vacuum system 196 is in communication with a pumping channel 197formed in the chamber body 102 to evacuate gases from the chamber 100and to help maintain a desired pressure or a desired pressure rangeinside the chamber 100. Control unit 176 may be coupled to the chamber100 to control processing conditions.

Soak with a Silicon Precursor

FIG. 5 is a flow chart illustrating another embodiment of a process ofintegrating a Ti layer and a TiN layer by soaking a Ti layer with a flowof a silicon precursor prior to deposition of a TiN layer thereover. Instep 502, a Ti layer is deposited over a substrate structure. The Tilayer may be deposited by methods including, but are not limited to,chemical vapor deposition, cyclical deposition, physical vapordeposition, and combinations thereof. For example, the Ti layer may bedeposited by chemical vapor deposition or cyclical deposition byutilizing a titanium precursor, such as titanium tetrachloride (TiCI₄),and a reducing agent, such as a hydrogen plasma. Examples of othertitanium containing compounds include, but are not limited to, titaniumiodide (TiI₄), titanium bromide (TiBr₄), other titanium halides,tetrakis(dimethylamido) titanium (TDMAT), tetrakis(diethylamido)titanium (TDEAT), other titanium organic compounds and derivativesthereof. The hydrogen plasma is preferably provided by utilizing ahydrogen gas (H₂). Other hydrogen containing gases which may also beused include silane (SiH₄), borane (BH₃), diborane (B₂H₆), andtriborane, among others.

Referring to step 504, after the Ti layer is deposited, the Ti layer istreated with a soak with a silicon precursor by flowing in the siliconprecursor into a process chamber. The silicon precursor is preferablysilane (SiH₄). Other silicon precursors may also be used, such asdisilane (Si₂H₆), and less preferably, dichlorosilane, or silicontetrachloride. The silicon precursor may be flowed in with a carriergas, such as a helium gas (He), an argon gas (Ar), hydrogen gas (H₂),nitrogen gas (N₂), other suitable gases, and combinations thereof. Thesubstrate is preferably maintained at a substrate temperature of about550° C. or less, preferably about 500° C. or less, and more preferablyabout 450° C. or less. Not wishing to be bound by theory, it is believedthat a soak of the Ti layer with a silicon precursor converts at least aportion of the Ti layer to titanium silicide (TiSi_(x)). It is believedthat the TiSi_(x) helps protect the interface between the Ti layer and asubsequently deposited TiN layer resulting in improved adhesion of theTiN layer thereover. It is believed that a soak with a silicon precursorperformed at a heater temperature of about 550° C. or less reduces theformation of polysilicon or amorphous silicon which would be undesirabledue to the higher resistance of polysilicon or amorphous silicon incomparison to TiSi_(x).

In step 506, after the SiH₄ soak, a TiN layer is deposited over thetreated Ti layer. The TiN layer may be deposited by such methods, withinclude, but are not limited to, chemical vapor deposition, cyclicaldeposition, physical vapor deposition, and combinations thereof. Forexample, the TiN layer may be deposited by chemical vapor deposition orcyclical deposition by utilizing a titanium precursor, such as titaniumtetrachloride (TiCl₄), and a nitrogen precursor, such as ammonia (NH₃)or a nitrogen plasma. When a titanium halide is used to form the TiNlayer, it is believed that the TiSi_(x) formed during the soak with asilicon precursor protects the Ti layer from etching or attack from thehalogen in the titanium halide, such as chlorine from TiCI₄, used duringchemical vapor deposition or cyclical deposition of the TiN layer.

Examples of other titanium containing compounds which may be used toform the TiN layer include, but are not limited to, titanium iodide(Til₄), titanium bromide (TiBr₄), other titanium halides,tetrakis(dimethylamido) titanium (TDMAT), tetrakis(diethylamido)titanium (TDEAT), other titanium organic compounds, and derivativesthereof. Examples of other nitrogen precursors which may be used to formthe TiN layer include, but are not limited to hydrazine (N₂H₄), otherN_(x)H_(y) compounds with x and y being integers, dimethyl hydrazine((CH₃)₂N₂H₂), t-butylhydrazine (C₄H₉N₂H₃), phenylhydrazine (C₆H₅N₂H₃),2,2′-azotertbutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), and derivativesthereof. Examples of other nitrogen containing gases which may also beused to generate a nitrogen plasma to form the TiN layer include, butare not limited to, NH₃, N_(x)H_(y) with x and y being integers (e.g.,hydrazine (N₂H₄)), a mixture of hydrogen gas (H₂) and nitrogen gas (N₂),mixtures thereof, other gases or gas mixtures containing hydrogen andnitrogen.

In one embodiment, step 502, step 504, and step 506 may each beperformed in separate chambers. In another embodiment, two or more ofstep 502, step 504, and step 506 may be performed in the same chamber.For example, deposition of a Ti layer and a soak of the Ti layer with asilicon precursor may be performed in the same chamber. In anotherexample, a soak of a Ti layer with a silicon precursor and deposition ofa TiN layer may be performed in the same chamber. In still anotherexample, deposition of a Ti layer, a soak of the Ti layer with a siliconprecursor, and deposition of a TiN over the treated Ti layer may beperformed in the same chamber. Preferably, two or more of step 502, step504, and step 506 are performed in the same chamber to increasethroughput of processing the substrates.

Processing chambers which may be used to deposit a Ti layer, perform asoak with a silicon precursor, and/or deposit a TiN layer include thechamber as described in reference to FIGS. 4 and 4A. Other chambers mayalso be used such as the processing chamber described in U.S. Ser. No.10/032,293, entitled “Chamber Hardware Design For Titanium NitrideAtomic Layer Deposition,” filed on Dec. 21, 2001, and published as US2003-0116087; the processing chamber described in U.S. Ser. No.10/016,300, entitled “Lid Assembly For A Processing System To FacilitateSequential Deposition Techniques,” filed on Dec. 12, 2001, and issued asU.S. Pat. No. 6,878,206, which claims priority to U.S. Ser. No.60/305,970, filed on Jul. 16, 2001; and the process chamber disclosed inU.S. Ser. No. 10/032,284, entitled “Gas Delivery Apparatus and MethodFor Atomic Layer Deposition,” filed on Dec. 21, 2001, and issued as U.S.Pat. No. 6,916,398, which claims priority to U.S. Ser. No. 60/346,086,entitled “Method and Apparatus for Atomic Layer Deposition,” filed onOct. 26, 2001, which are all herein incorporated by reference in theirentirety to the extent not inconsistent with the present disclosure.

One exemplary process of treating a Ti layer with a soak of a siliconprecursor comprises flowing in silane (SiH₄) into a chamber, such aschamber 100 described in reference to FIG. 4, at a flow rate betweenabout 5 sccm and about 500 sccm, preferably about 100 sccm. Silane maybe introduced with a carrier gas, such as a helium gas (He), an argongas (Ar), hydrogen gas (H₂), nitrogen gas (N₂), other suitable gases,and combinations thereof. The chamber may be maintained at a pressurebetween about 0.1 Torr to about 50 Torr, preferably about 3 Torr. Thesubstrate is preferably maintained at a substrate temperature about 550°C. or less, preferably about 500° C. or less, and more preferably about450° C. or less. The SiH₄ soak is preferably carried out for a timeperiod between about 5 seconds and about 60 seconds. In general,treatment time will depend on the flow rate of SiH₄ and the pressure ofthe chamber.

Applications

FIG. 6 is a schematic cross-sectional view of one embodiment of anexemplary application of an integrated Ti/TiN film stack formed by theprocess of FIG. 1 or FIG. 5. As shown in FIG. 6, a doped source/drainregion 845 may be formed over a substrate 852 within film stack 850. Thesubstrate 852 may be a semiconductor substrate, such as a siliconsubstrate. A dielectric layer 858, such as a silicon dioxide layer or alow-k dielectric layer, may be formed over the substrate 852. Oneexample of a low-k dielectric layer is an oxidized organosilane layer oran oxidized organosiloxane layer described in more detail in U.S. Pat.No. 6,348,725, which is incorporated by reference herein. The dielectriclayer 858 may be patterned and etched to form an aperture. A titaniumlayer 859 may be deposited over the aperture to form titanium silicide856 in situ or in an annealing step. A passivation layer 860 comprisingTiSi_(x), TiSi_(x)N_(y), or combinations thereof is deposited over thetitanium layer 859 or formed by a soak of the titanium layer 859 with asilicon precursor. A TiN layer 861 is deposited over the passivationlayer 860. A conductive layer 862 comprising a conductive material, suchas tungsten, copper, aluminum, and combinations thereof, may bedeposited over the TiN layer 861.

FIG. 7 is a schematic cross-sectional view of another embodiment of anexemplary application of an integrated Ti/TiN film stack formed by theprocess of FIG. 1 or FIG. 5. As shown in FIG. 7, the film stack 1200includes an underlying substrate 1202, such as a semiconductorsubstrate, and includes a doped source/drain region 1204. A metalsilicide layer 1206, such as a titanium silicide layer, nickel silicidelayer, cobalt silicide layer, or tungsten silicide layer, may be formedover the region 1204. A dielectric layer 1208, such as a silicon dioxidelayer or a low-k dielectric layer, may be formed over the metal silicidelayer 1206. One example of a low-k dielectric layer is an oxidizedorganosilane layer or an oxidized organosiloxane layer described in moredetail in U.S. Pat. No. 6,348,725, which is incorporated by referenceherein. The dielectric layer 1208 may be patterned and etched to form anaperture exposing the metal silicide layer 1206. A titanium layer 1212may be formed over the aperture. A passivation layer 1214 comprisingTiSi_(x), TiSi_(x)N_(y), or combinations thereof is deposited over thetitanium layer 1212 or formed by a soak of the titanium layer 1212 witha silicon precursor. A titanium nitride layer 1216 may be formed overthe passivation layer 1214. A conductive layer 1222 comprising aconductive material, such as tungsten, copper, aluminum, andcombinations thereof, may be deposited over the titanium nitride layer1216. Other applications of the integrated Ti/TiN film stack arepossible.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A method for forming a metal-containing material on a substrate,comprising: forming a titanium-containing layer on a substrate by aplasma-enhanced cyclical vapor deposition process; exposing thesubstrate to a silicon-containing compound during a soak process; anddepositing a conductive material comprising copper on the substrate by asecond vapor deposition process.
 2. The method of claim 1, wherein ametal nitride layer comprising titanium is deposited subsequent to thesoak process and prior to the second vapor deposition process.
 3. Themethod of claim 1, wherein the silicon-containing compound is selectedfrom the group consisting of silane, disilane, chlorosilane,dichlorosilane, trichlorosilane, tetrachlorosilane, hexachlorodisilane,derivatives thereof, and combinations thereof.
 4. The method of claim 3,wherein the silicon-containing compound is silane.
 5. The method ofclaim 1, wherein the titanium-containing layer comprises titaniumnitride.
 6. The method of claim 1, wherein the titanium-containing layercomprises titanium nitride formed by exposing the substrate to anitrogen precursor during the plasma-enhanced cyclical vapor depositionprocess.
 7. The method of claim 6, wherein the nitrogen precursorcomprises a gas selected from the group consisting of nitrogen,hydrogen, a nitrogen/hydrogen mixture, ammonia, hydrazine, hydrazinecompounds, derivatives thereof, and combinations thereof.
 8. The methodof claim 6, wherein the nitrogen precursor comprises ammonia.
 9. Themethod of claim 6, wherein the nitrogen precursor comprises a nitrogenplasma.
 10. A method for forming a metal-containing material on asubstrate, comprising: forming a metal-containing barrier layer on asubstrate by a plasma-enhanced cyclical vapor deposition process;exposing the substrate to a silicon-containing compound during a soakprocess to form a pretreated surface on the metal-containing barrierlayer; and depositing a tungsten material on the substrate by a vapordeposition process.
 11. The method of claim 10, wherein a metal nitridelayer is deposited on the pretreated surface prior to depositing thetungsten material.
 12. The method of claim 10, wherein the tungstenmaterial is deposited by a cyclic layer deposition process.
 13. Themethod of claim 10, wherein the tungsten material is deposited by aplasma-enhanced cyclic layer deposition process.
 14. The method of claim10, wherein the silicon-containing compound is selected from the groupconsisting of silane, disilane, chlorosilane, dichlorosilane,trichlorosilane, tetrachlorosilane, hexachlorodisilane, derivativesthereof, and combinations thereof.
 15. The method of claim 14, whereinthe silicon-containing compound is silane and the metal-containingbarrier layer comprises titanium.
 16. A method for forming ametal-containing material on a substrate, comprising: forming ametal-containing barrier layer on a substrate by a plasma-enhancedcyclical vapor deposition process, wherein the metal-containing barrierlayer comprises titanium nitride formed by exposing the substrate to anitrogen precursor during the plasma-enhanced cyclical vapor depositionprocess; exposing the substrate to a silicon precursor during a soakprocess to form a pretreated surface on the metal-containing barrierlayer; and depositing a tungsten material on the substrate by a vapordeposition process.
 17. The method of claim 16, wherein the nitrogenprecursor comprises a gas selected from the group consisting ofnitrogen, hydrogen, a nitrogen/hydrogen mixture, ammonia, hydrazine,hydrazine compounds, derivatives thereof, and combinations thereof. 18.The method of claim 17, wherein the nitrogen precursor comprises ammoniaor nitrogen.
 19. A method for forming a metal-containing material on asubstrate, comprising: forming a metal-containing barrier layer on asubstrate by a plasma-enhanced cyclical vapor deposition process;exposing the substrate to a soak process to form a pretreated surface onthe metal-containing barrier layer; depositing a metal nitride layer onthe pretreated surface; and depositing a copper material on the metalnitride layer by a vapor deposition process.
 20. The method of claim 19,wherein the copper material is deposited by a plasma-enhanced vapordeposition process.
 21. A method for forming a metal-containing materialon a substrate, comprising: forming a metal-containing barrier layer ona substrate by a plasma-enhanced cyclical vapor deposition process;exposing the substrate to a silicon-containing compound during the soakprocess to form a pretreated surface on the metal-containing barrierlayer; and depositing a material comprising copper on the substrate by avapor deposition process.
 22. The method of claim 21, wherein thesilicon-containing compound is selected from the group consisting ofsilane, disilane, chlorosilane, dichlorosilane trichlorosilane,tetrachlorosilane, hexachlorodisilane, derivatives thereof, andcombinations thereof.
 23. The method of claim 22, wherein thesilicon-containing compound is silane and the metal-containing barrierlayer comprises titanium.
 24. A method for forming a metal-containingmaterial on a substrate, comprising: forming a metal-containing barrierlayer on a substrate by a plasma-enhanced cyclical vapor depositionprocess, wherein the metal-containing barrier layer comprises titaniumnitride formed by exposing the substrate to a nitrogen precursor duringthe plasma-enhanced cyclical vapor deposition process; exposing thesubstrate to a soak process to form a pretreated surface on themetal-containing barrier layer; and depositing a material comprisingcopper on the substrate by a vapor deposition process.
 25. The method ofclaim 24, wherein the nitrogen precursor comprises a gas selected fromthe group consisting of nitrogen, hydrogen, a nitrogen/hydrogen mixture,ammonia, hydrazine, hydrazine compounds, derivatives thereof, andcombinations thereof.
 26. The method of claim 25, wherein the nitrogenprecursor comprises ammonia or nitrogen.
 27. A method for forming ametal-containing material on a substrate, comprising: forming ametal-containing barrier layer on a substrate by a plasma-enhancedcyclical vapor deposition process by sequentially exposing the substrateto a metal-containing precursor and a nitrogen precursor; exposing thesubstrate to a soak process to form a pretreated surface on themetal-containing barrier layer; and depositing a conductive material onthe substrate by a vapor deposition process.
 28. The method of claim 27,wherein the nitrogen precursor comprises a gas selected from the groupconsisting of nitrogen, hydrogen, a nitrogen/hydrogen mixture, ammonia,hydrazine, hydrazine compounds, derivatives thereof, and combinationsthereof.
 29. The method of claim 28, wherein the nitrogen precursorcomprises ammonia or nitrogen, and the conductive material comprisestungsten or copper.
 30. The method of claim 29, wherein the substrate isexposed to a silane during the soak process.
 31. A method for forming ametal-containing material on a substrate, comprising: forming ametal-containing barrier layer on a substrate by a plasma-enhancedcyclical vapor deposition process by sequentially exposing the substrateto a metal-containing precursor and a nitrogen precursor, wherein themetal-containing precursor comprises methylamido or ethylamido ligands,and the nitrogen precursor comprises a gas selected from the groupconsisting of nitrogen, hydrogen, a nitrogen/hydrogen mixture, ammonia,hydrazine, hydrazine compounds, derivatives thereof, and combinationsthereof; exposing the substrate to a soak process to form a pretreatedsurface on the substrate; and depositing a conductive material on thesubstrate by a vapor deposition process, wherein the conductive materialcomprises tungsten or copper.
 32. The method of claim 31, wherein themetal-containing precursor comprises tetrakis(dimethylamido) titanium,tetrakis(diethylamido) titanium, or derivatives thereof.
 33. The methodof claim 31, wherein the nitrogen precursor comprises ammonia ornitrogen plasma, and the conductive material comprises copper.
 34. Themethod of claim 31, wherein the substrate is exposed to asilicon-containing compound during the soak process.
 35. The method ofclaim 34, wherein the silicon-containing compound is selected from thegroup consisting of silane, disilane, chiorosilane, dichlorosilane,trichlorosilane, tetrachiorosilane, hexachiorodisilane, derivativesthereof, and combinations thereof.
 36. The method of claim 35, whereinthe nitrogen precursor comprises ammonia or nitrogen plasma, and thesilicon-containing compound comprises silane.